Hi all,
I’d like to develop a mini-filter driver which can reduce filesize during copy operation.
Detailed condition is the following…
・Files are on the volume which is attached by the mini-filter.
・When they are copied to another volume which is NOT attached by the mini-filter, the size of each file is reduced. For example, when a 4096byte file is copied from a mini-filter attached volume to non-attached volume, the first 3584bytes from the beginning is copied and the last 512byte is not copied.
I’d like to have any good idea to realize this.
Satoru
Write a custom copy app in user mode instead.
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Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
wrote in message news:xxxxx@ntfsd…
Hi all,
I’d like to develop a mini-filter driver which can reduce filesize during copy
operation.
Detailed condition is the following…
・Files are on the volume which is attached by the mini-filter.
・When they are copied to another volume which is NOT attached by the
mini-filter, the size of each file is reduced. For example, when a 4096byte
file is copied from a mini-filter attached volume to non-attached volume, the
first 3584bytes from the beginning is copied and the last 512byte is not
copied.
I’d like to have any good idea to realize this.
-----------
Satoru
This is not possible to achieve in filter driver.
At least not exactly as you are describing.
Yes, it’s possible to write compression filter who will
compress every file on a volume (or in a directory).
But there’s no way how to detect copy operation
in filter driver level.
L.
Sorry for my short explanation.
Actually, i need such technique for on-the-fly encryption filter.
Copying files on attached volume to no-attached volume means that reading encrypted files, removing a header, decrypting contents, removing a padding area and writing decrypted contents to non-attached volume. Then, removing a header and a padding area involves reducing filesize.
So what I’d like to know is a technique for deceiving file size.